The present invention relates to a process for the industrial manufacture of 4-phenyl-1,3-dioxane from styrene, according to the general equation ##STR1## Various laboratory methods for preparing 4-phenyl-1,3-dioxane, according to the general procedure described by Prins (Chem. Weekblad 14, 932, 1917; 16, 1072 and 1510, 1919) by the reaction between styrene and formaldehyde, are known in the art (see, e.g., Organic Syntheses, Coll. Vol. IV, 786, 1963). Yet, none of the hitherto known methods are suitable for the production of 4-phenyl-1,3-dioxane on an industrial scale. The various drawbacks of the prior art methods include:
(a) the use of excessive amounts of formaldehyde; PA1 (b) need of solvents; and PA1 (c) extensive and uneconomical working-up for the recovery of the final product from the reaction mixture.
4-Phenyl-1,3-dioxane is a high-boiling liquid, which is useful as an industrial high-boiling solvent. It has also been reported to have utility as a plasticizer (e.g., for celluloid), curing agent (e.g., for phenolic resins), and pigment dispersant. Furthermore, it has been used, both as a monomer and as an additive, in the production of plastic polymers; in particular, it has been utilized as a component in both phenolic and styrenic systems.